Polyphase disconnecting switch for high-voltage circuit having a conductor at each apex of a triangle

ABSTRACT

Disconnecting switch assemblies are located in a triangular configuration on an inverted cross-shaped frame adapted to be secured to the top of a power line pole. Each switch assembly includes a pivotally mounted insulator carrying a switch blade for engaging a stationary contact carried by a stationary insulator. The pivoted insulators at the ends of the transverse piece are interconnected by a shaft which is connected by a link to the pivoted insulator at the top of the upright piece to effect conjoint switch operation. The transverse and vertical pieces are tubular and the shaft and link are enclosed thereby. Dead end connections adjacent the switch assemblies permit dead ending the respective conductor thereto. Each switch blade and the respective switch contact are so positioned that the switch blade cannot gravitate to the open position when closed and vice versa. Each switch contact is carried by an insulator that is mounted at the distal end of a support bracket in angular relation to the respective pivoted insulator.

United States Patent Bernatt et al.

[ Mar. 7, 1972 [54] POLYPHASE DISCONNECTING Attorney-Robert R. Lockwood SWITCH FOR HIGH-VOLTAGE CIRCUIT HAVING A CONDUCTOR AT [571 ABSTRACT EACH APEX OF A TRIANGLE Disconnecting switch assemblies are located in a triangular I configuration on an inverted cross-shaped frame adapted to [72] Inventors i gm gz ggfzt'gfig g z '52:? lm be secured to the top of a power line pole. Each switch asp sembly includes a pivotally mounted insulator carrying a [73] Assignec: S & C Electric Company, Chicago, Ill. switch blade for engaging a stationary contact carried by a stationary insulator. The pivoted insulators at the ends of the [22] 1971 transverse piece are interconnected by a shaft which is con- [21] Appl. No.: 104,549 nected by a link to the pivoted insulator at the top of the upright piece to effect conjoint switch operation. The transverse and vertical pieces are tubular and the shaft and link are U.S.Cl enclosed thereby Dead end connections adj-mm the swimh [58] Field of Search [48 RP 48 assemblies permit dead ending the respective conductor thereto. Each switch blade and the respective switch Contact are so positioned that the switch blade cannot gravitate to the [56] References cued open position when closed and vice versa. Each switch Contact UNTTED STATES PATENTS is carried by an insulator that is mounted at the distal end of a support bracket in angular relation to the respective pivoted 3,553,412 1/1971 Kerr, Jr ..200/48 insulator Primary Examiner-Herman J. Hohauser 16 Claims, 5 Drawing Figures Patented March 7, 1972 3,647,996

3 Sheets-Sheet Patented March 7, 1972 s Sheets-Sheet Patented March 7, 1972 3,647,996

3 Sheds-Sheet 3 POLYPHASE DISCONNECTING SWITCH FOR HIGH- VOLTAGE CIRCUIT HAVING A CONDUCTOR AT EACH APEX OF A TRIANGLE Three phase electric power distribution conductors often are located in a triangular configuration with a conductor being located at each apex. For this purpose and to provide improved appearance, an upright insulator is mounted onthe top of a powerline pole and two horizontal insulators are mounted at a lower level on opposite sides of the pole. The conductors are secured to the distal ends of the insulators with the arrangement being such that each conductor is located at the apex of a triangle which may be substantially an equilateral triangle. It is desirable to provide a three-phase or three-pole disconnecting switch construction for such a conductor arrangement that blends in with it to maintain the improved appearance.

Among the objects of this invention are: To arrange the individual phase switches of a three-phase switch to correspond closely to the positioning of the associated powerline conductors; to provide a prefabricated polyphase switch construction for this purpose that can be mounted at the top of a powerline pole; to provide a support frame in the form of an inverted cross having a vertical frame member or vertical piece secured to a horizontal frame member or horizontal piece intermediate the ends thereof with each end being located at the apex of a triangle; to mount a disconnecting switch assembly at each of the ends of the pieces forming the inverted cross or at each apex of the triangle; for each disconnecting switch assembly to employ a switch blade carried by a pivotable insulator for cooperation with a switch contact carried by a stationary insulator; to mount the stationary insulator in angular relation to the pivotable insulator; to provide for conjointly shifting the pivotable insulators between switch closed and switch open positions; to interconnect the pivotable insulators at the ends of the horizontal frame member or piece by a shaft; to interconnect the shaft by a link. to the pivotable insulator at the upper end of the vertical frame member or piece; to form the support frame of tubular members or pieces and to enclose the shaft and link therein; and to position the pivot axis of each switch blade with respect to its switch contact such that when closed the switch blade cannot gravitate to open position and when opened cannot gravitate to closed position.

In the drawings: FIG. 1 is an elevational view of a powerline pole on which the disconnecting switch construction embodying the present invention is mounted. FIG. 2 is a top plan view of the construction shown in FIG. 1 and illustrates diagrammatically how the three-phase conductors are connected thereto. FIG. 3 is an elevational view of the switch construction at an enlarged scale taken generally along line 3-3 of FIG. 2, certain parts being shown in section in order to illustrate certain internal details of construction. FIG. 4 is a view, in side elevation, taken generally along line 4-4 of FIG. 3, the upright piece being shown partly in section. FIG. 5 is a horizontal sectional view taken generally along line 5-5 of FIG. 4.

In FIGS. 1, 4 and 5 the reference character designates a powerline pole that may be circular in configuration and formed of wood. However, it may be formed of other material. Mounted at the upper end of the powerline pole 10 is a disconnecting switch construction that is indicated, generally, at 11. The disconnecting switch construction 11 is provided for interconnecting three conductors 12, 13 and 14 of a polyphase alternating current electric power transmission line each of which is located at the apex of a triangle which, as indicated above, may be substantially an equilateral triangle with the central conductor 13 mounted on insulators extending upwardly from a string of power line poles and the conductors l2 and 13 being located on insulators that extend laterally from the power line poles and below the conductor 13. Disconnecting switch assemblies 16, 17 and 18 are provided for controlling the connections between sections of the conductors 12, 13 and 14.

The disconnecting switch assemblies l6, l7 and 18 are mounted on inverted cross-shaped means, indicated generally at 19, and formed by a tubular upright 20 and a transverse piece 21, the latter being in two sections and welded at 22 to opposite sides of the upright 20. The upright and transverse pieces 20 and 21 are formed of suitable metal, such as steel, for example they may be formed of hollow steel members having cross-sectional dimensions of 4 inches by 6 inches. However,,it will be understood that other dimensions and shapes can be employed.

The inverted cross-shaped frame means 19, as indicated in FIG. 1, is mounted at the upper end of the power line pole 10. For this purpose openings 25 and 26, FIG. 3, are provided in one wall of the upright piece 20 for receiving bolts which extend through the powerline pole 10 and serve to prevent downward movement of the switch construction 11. Pairs of angles 27 and 28 are suitably welded to opposite sides of the upright piece 20 to which pole band mounting members can be secured to hold the frame means 19 in the position at the upper end of the powerline pole 10. For the purpose of centering the frame means 19 on the power line pole 10 a pair of mounting brackets, indicated at 29, in FIG. 4, is provided. As shown in FIG. 5 each of the mounting brackets 29 comprises a channel member 30 having secured therein an angle member 31, the latter being welded to the former and the mounting brackets 29 being welded to the upright piece 20.

Provision is made for dead ending the conductors l2, l3 and 14 on opposite sides of the switch construction 11 by means of dead end angles 32, 33 and 34. The angles 32 and 34, FIG. 3, are welded to the underside of the transverse piece 21 near its ends while the angle 33 is welded to the upright piece 20 near its upper end. The angles 32, 33 and 34 are located at the apices of a triangle which is outlined at 35. This triangle is generally equilateral, it being understood that the angle 33 is offset slightly from a central position since it is secured to one side of the upright piece 20. The location of the angles 32, 33 and 34 at the apices of the triangle indicated at 35 conforms generally to the positions of the conductors 12, 13 and 14. They are dead ended to the angles 32, 33 and 34 by insulators 36, 37 and 38 which are arranged in pairs and are secured to opposite ends of the angles 32, 33 and 34 in accordance with conventional practice.

The construction of the disconnecting switch assemblies l6, l7 and 18 is identical and a description of one will suffice for all of them. Each of the switch assemblies includes a pivotable insulator 40 that is arranged to pivot about a horizontal axis. At its distal end the insulator 40 carries a switch blade 41 for movement into and out of engagement with a stationary contact 42 that is mounted on a contact support bracket 43 at the distal end of a stationary insulator 44. The stationary insulator 44 is mounted on an outer section 45 of a support bracket that is indicated, generally, at 46. The inner end section 47 of the support bracket 46 is secured to the frame means 19. For the switch assemblies 16 and 18 the inner end section 47 is secured, as by welding, to the respective end of the transverse piece 21. For the inner end section 47 of the switch assembly 17 it is secured as by welding to a flat side of the upright piece 20 near the upper end. An intermediate section 48 at an obtuse angle to the inner end section 47 and at right angles to the outer section 45 interconnects these sections and provides a unitary construction. Associated with each stationary contact 42 is a load interrupter device 49 of conventional construction. A line terminal 51 is connected to each switch blade 41 at its pivoted end. A line terminal 52 is connected to each stationary contact 42 mounted on the respective stationary insulator 44.

As illustrated in FIG. 2 jumper conductors 54, 55 and 56 interconnect one section of the conductors 12, 13 and 14 to the line terminals 51. Jumper conductors 58, 59 and 60 interconnect the other section of the conductors 12, 13 and 14 to the line terminals 52.

As illustrated in FIG. 3 the pivotable insulators 40 of the switch assemblies 16 and 18 are connected to the ends of a shaft 63 which is journaled within the transverse piece 21 and on the inner end sections 47 of the support brackets 46. The

pivotable insulator 40 of the switch assembly 17 is secured to a shaft 64 which is pivoted in the upper end of the upright piece 20. An arm 65 extends radially from the shaft 64 and is pivoted to the upper end of a link 66 which extends downwardly inside the tubular upright piece and at its lower end, as shown in FIG. 4, is pivotally connected to one end 67 of a lever 68 that is secured to the shaft 63 midway its ends. The other end 69 of the lever 68 is pivotally connected to the upper end ofan upper link 70, FIG. 1, which, in turn, is pivoted at 71 to the upper end of a lower link 72. At the lower end of the lower link 72 an operating handle 73 is pivotally connected thereto for the purpose of permitting manual operation of the switch construction 11.

For the purpose of preventing entrance of extraneous material into the tubular upright piece 20 suitable screens 74 are secured on the upper and lower ends. At the upper end, instead of a screen 74, a cover can be used.

In operation, the operating handle 73 as swung from its position shown in FIG. 1 in a counterclockwise direction to move the upper and lower links 70 and 72 downwardly for the purpose of pivoting the shaft 63 and thereby, through link 66, the shaft 64 to pivot the insulators 40 and switch blades 41 carried thereby from the positions as shown by full lines through approximately 90 to the position FIG. 4 shown by broken lines. This is accompanied by disconnecting the distal ends of the switch blades 41 from the stationary contacts 42 and transferring the current flow to the load interrupter devices 49 where the circuit is interrupted and any are incident thereto is extinguished. The reverse action takes place when the operating handle 73 is swing upwardly in a clockwise direction although the circuit first is completed between the switch blades 41 and the respective stationary contacts 42 followed by closure of the respective load interrupter devices 49.

In FIG. 4 it will be observed that the switch blades 41 in the switch closed position are located to one side of a central position. Thus it is not possible for them to gravitate from this position to the switch open position. Also, as here shown, when the switch blades occupy the switch open positions, they are located past the central upright position and it is not possible for them to gravitate to the switch closed position.

We claim:

I. In combination, a high voltage circuit comprising three conductors each located at the apex of a triangle, a powerline pole supporting said conductors extending laterally thereof, frame means in a plane generally at right angles to said conductors and secured to the upper end of said pole including a horizontal frame member and a vertical frame member secured to said horizontal frame member intermediate its ends, and a disconnecting switch assembly mounted on each end of said horizontal frame member and on the upper end of said vertical frame member near the respective apex of said triangle and connected to the respective conductor for interconnecting adjacent sections thereof.

2. Disconnecting switch construction for interconnecting conductors of a three-phase high voltage circuit each located at the apex ofa triangle and for mounting on a powerline pole comprising: frame means adapted to be secured to the upper end of said pole including a horizontal frame member and a vertical frame member secured to said horizontal frame member intermediate its ends, a disconnecting switch assembly mounted on each end of said horizontal frame member and on the upper end of said vertical frame member with each switch assembly located near each apex of said triangle, and operating means on said frame means mechanically interconnecting said disconnecting switch assemblies for conjoint operation thereof between open and closed positions.

3. Disconnecting switch constnrction according to claim 1 wherein dead end means are mounted near each end of said horizontal frame member and the upper end of said vertical frame member to which said conductors can be dead ended for connection to the respective switch assembly.

4. Disconnecting switch construction according to claim 1 wherein each switch assembly includes a stationary contact and a cooperating switch blade carried by an insulator, means pivotally mount the insulators of the switch assemblies at the ends of said horizontal frame member endwise thereof, and means pivotally mount the insulator of the switch assembly at the upper end of said vertical frame member transversely thereof.

5. Disconnecting switch construction for interconnecting conductors of a three-phase high voltage circuit each located at the apex of a triangle and for mounting on a powerline pole comprising: frame means adapted to be secured to the upper end of said pole including a horizontal frame member and a vertical frame member secured to said horizontal frame member intermediate its ends, a disconnecting switch assembly mounted on each end of said horizontal frame member and on the upper end of said vertical frame member with each switch assembly located near each apex of said triangle, each switch assembly including a stationary contact and a cooperating switch blade carried by an insulator, means pivotally mounting the insulators of the switch assemblies at the ends of said horizontal frame member endwise thereof, means pivotally mounting the insulator of the switch assembly at the upper end of said vertical frame member transversely thereof; shaft means interconnecting said insulators of said switch assemblies at the ends of said horizontal frame member, and link means interconnecting said insulator of said switch assembly at the upper end of said vertical frame member and said shaft means to effect conjoint operation of said switch blades into and out of engagement with the respective stationary contact.

6. Disconnecting switch construction according to claim 5 wherein said horizontal and vertical frame members are tubular and said shaft means and said link means are located respectively in said horizontal and vertical frame members.

7. Disconnecting switch construction according to claim 4 wherein each of said insulators is mounted to pivot about a horizontal axis to shift said switch blade from engagement with the respective stationary contact to one side of a vertical position to the other side of said vertical position out of engagement with the respective contact whereby said switch blade in the switch closed position cannot gravitate to switch open position and in the switch open position cannot gravitate to the switch closed position.

8. Disconnecting switch construction according to claim 4 wherein an insulator support bracket is secured to each end of said horizontal frame member and to the upper end of said vertical frame member for supporting an insulator at one end on the other end of which the respective stationary contact is mounted.

9. Disconnecting switch construction for interconnecting conductors of a three-phase high voltage circuit each located at the apex of a triangle and for mounting on a powerline pole comprising: frame means adapted to be secured to the upper end of said pole including a horizontal frame member and a vertical frame member secured to said horizontal frame member intermediate its ends, a disconnecting switch assembly mounted on each end of said horizontal frame member and on the upper end of said vertical frame member with each switch assembly located near each apex of said triangle, each switch assembly including a stationary contact and a cooperating switch blade carried by an insulator, means pivotally mounting the insulators of the switch assemblies at the ends of said horizontal frame member endwise thereof, means pivotally mounting the insulator of the switch assembly at the upper end of said vertical frame member transversely thereof, and an insulator support bracket secured to each end of said horizontal frame member and to the upper end of said vertical frame member for supporting an insulator at one end on the other end of which the respective stationary contact is mounted, each of said support brackets having an inner end section for mounting flatwise against the respective end of the respective frame member, an intermediate section extending at an obtuse angle from said inner end section, and an outer section extending at right angles from said intermediate section for mounting the respective contact carrying insulator in angular relation to the respective pivoted insulator.

10. In combination, a high voltage circuit comprising two sets of three conductors in endwise relation constituting a three-phase powerline with corresponding conductors each located at the apex of a triangle, a powerline pole supporting said conductors extending laterally thereof, inverted crossshaped frame means in a plane generally at right angles to said conductors with the upright piece secured to the upper end of said pole and the ends of the upright and transverse pieces each being located near the respective apex of said triangle, a disconnecting switch assembly mounted at each of said ends of said upright and transverse pieces, operating means on said frame means mechanically interconnecting said disconnecting switch assemblies for conjoint operation thereof between open and closed positions, and dead end means near each of said ends of said upright and transverse pieces to which said conductors can be dead ended for connection to the respective switch assembly.

11. Disconnecting switch construction according to claim wherein each switch assembly includes a stationary contact and a cooperating switch blade carried by an insulator and means pivotally mount the insulators of the switch assemblies at said ends of said upright and transverse pieces, said operating means being connected to said insulators.

12. Disconnecting switch construction according to claim 11 wherein said operating means includes shaft means interconnecting said insulators at the ends of said transverse piece, and link means interconnecting said insulator at said end of said upright piece and said shaft means.

13. Disconnecting switch construction according to claim 12 wherein said upright and transverse pieces are tubular and said link means and said shaft means are located respectively in said upright and transverse pieces.

l4. Disconnecting switch construction according to claim 11 wherein each of said insulators is mounted to pivot about a horizontal axis to shift said switch blade from engagement with the respective stationary contact to one side of a vertical position to the other side of said vertical position out of engagement with the respective contact whereby said switch blade in the switch closed position cannot gravitate to switch open position and in the switch open position cannot gravitate to the switch closed position.

15. Disconnecting switch construction according to claim 11 wherein an insulator support bracket is secured to each end of said horizontal frame member and to the upper end of said vertical frame member for supporting an insulator at one end on the other end of which the respective stationary contact is mounted.

l6. Disconnecting switch construction for interconnecting conductors of a three-phase high voltage circuit each located at the apex of a triangle and for mounting on a power line pole comprising: inverted cross-shaped frame means with the upright piece adapted to be secured to the upper end of said pole and the ends of the upright and transverse pieces each being located near the respective apex of said triangle, a disconnecting switch assembly mounted at each of said ends of said upright and transverse pieces, operating means on said frame means mechanically interconnecting said disconnecting switch assemblies for conjoint operation thereof between open and closed positions, dead end means near each of said ends of said upright and transverse pieces to which said conductors can be dead ended for connection to the respective switch assembly; each switch assembly including a stationary contact and a cooperating switch blade carried by an insulator and means pivotally mounting the insulators of the switch assemblies at said ends of said upright and transverse pieces, said operating means being connected to said insulators; and an insulator support bracket secured to each end of said horizontal frame member and to the upper end of said vertical frame member for supporting an insulator at one end on the other end of which the respective stationary contact is mounted, each of said support brackets having an inner end section for mounting flatwise against the respective end of the respective frame member, an intermediate section extending at an obtuse angle from said inner end section, and an outer section extending at right angles from said intermediate section for mounting the respective contact carrying insulator in angular relation to the respective pivoted insulator.

Disclaimer 3,647,996.J0seph Bematt, Arlington Heights, and John T. Gutnwnn, Prospect Heights, 111. POLYPHASE DISCONNECTING SWITCH F OR HIGH VOLTAGE CIRCUIT HAVING A CONDUCTOR AT EACH APEX OF A TRIANGLE. Patent dated Mar. 7 1972. Disclaimer filed J an. 30, 1980, by the assignee, S (Q: 6' Electm'c Company. Hereby enters this disclaimer to claims 1, 2, 3, 10, 11 and 12 of said patent.

[Ofioial Gazette, A pm'l 8, 1980.] 

1. In combination, a high voltage circuit comprising three conductors each located at the apex of a triangle, a powerline pole supporting said conductors extending laterally thereof, frame means in a plane generally at right angles to said conductors and secured to the upper end of said pole including a horizontal frame member and a vertical frame member secured to said horizontal frame member intermediate its ends, and a disconnecting switch assembly mounted on each end of said horizontal frame member and on the upper end of said vertical frame member near the respective apex of said triangle and connected to the respective conductor for interconnecting adjacent sections thereof.
 2. Disconnecting switch construction for interconnecting conductors of a three-phase high voltage circuit each located at the apex of a triangle and for mounting on a powerline pole comprising: frame means adapted to be secured to the upper end of said pole including a horizontal frame member and a vertical frame member secured to said horizontal frame member intermediate its ends, a disconnecting switch assembly mounted on each end of said horizontal frame member and on the upper end of said vertical frame member with each switch assembly located near each apex of said triangle, and operating means on said frame means mechanically interconnecting said disconnecting switch assemblies for conjoint operation thereof between open and closed positions.
 3. Disconnecting switch construction according to claim 1 wherein dead end means are mounted near each end of said horizontal frame member and the upper end of said vertical frame member to which said conductors can be dead ended for connection to the respective switch assembly.
 4. Disconnecting switch construction according to claim 1 wherein each switch assembly includes a stationary contact and a cooperating switch blade carried by an insulator, means pivotally mount the insulators of the switch assemblies at the ends of said horizontal frame member endwise thereof, and means pivotally mount the insulator of the switch assembly at the upper end of said vertical frame member transversely thereof.
 5. Disconnecting switch construction for interconnecting conductors of a three-phase high voltage circuit each located at the apex of a triangle and for mounting on a powerline pole comprising: frame means adapted to be secured to the upper end of said pole including a horizontal frame member and a vertical frame member secured to said horizontal frame member intermediate its ends, a disconnecting switch assembly mounted on each end of said horizontal frame member and on the upper end of said vertical frame member with each switch assembly located near each apex of said triangle, each switch assembly including a stationary contact and a cooperating switch blade carried by an insulator, means pivotally mounting the insulators of the switch assemblies at the ends of said horizontal frame member endwise thereof, means pivotally mounting the insulator of the switch assembly at the upper end of said vertical frame member transversely thereof; shaft means interconnecting said insulators of said switch assemblies at the ends of said horizontal frame member, and link means interconnecting said insulator of said switch assembly at the upper end of said vertical frame member and said shaft means to effect conjoint operation of said switch blades into and out of engagement with the respective stationary contact.
 6. Disconnecting switch construction according to claim 5 wherein said horiZontal and vertical frame members are tubular and said shaft means and said link means are located respectively in said horizontal and vertical frame members.
 7. Disconnecting switch construction according to claim 4 wherein each of said insulators is mounted to pivot about a horizontal axis to shift said switch blade from engagement with the respective stationary contact to one side of a vertical position to the other side of said vertical position out of engagement with the respective contact whereby said switch blade in the switch closed position cannot gravitate to switch open position and in the switch open position cannot gravitate to the switch closed position.
 8. Disconnecting switch construction according to claim 4 wherein an insulator support bracket is secured to each end of said horizontal frame member and to the upper end of said vertical frame member for supporting an insulator at one end on the other end of which the respective stationary contact is mounted.
 9. Disconnecting switch construction for interconnecting conductors of a three-phase high voltage circuit each located at the apex of a triangle and for mounting on a powerline pole comprising: frame means adapted to be secured to the upper end of said pole including a horizontal frame member and a vertical frame member secured to said horizontal frame member intermediate its ends, a disconnecting switch assembly mounted on each end of said horizontal frame member and on the upper end of said vertical frame member with each switch assembly located near each apex of said triangle, each switch assembly including a stationary contact and a cooperating switch blade carried by an insulator, means pivotally mounting the insulators of the switch assemblies at the ends of said horizontal frame member endwise thereof, means pivotally mounting the insulator of the switch assembly at the upper end of said vertical frame member transversely thereof, and an insulator support bracket secured to each end of said horizontal frame member and to the upper end of said vertical frame member for supporting an insulator at one end on the other end of which the respective stationary contact is mounted, each of said support brackets having an inner end section for mounting flatwise against the respective end of the respective frame member, an intermediate section extending at an obtuse angle from said inner end section, and an outer section extending at right angles from said intermediate section for mounting the respective contact carrying insulator in angular relation to the respective pivoted insulator.
 10. In combination, a high voltage circuit comprising two sets of three conductors in endwise relation constituting a three-phase powerline with corresponding conductors each located at the apex of a triangle, a powerline pole supporting said conductors extending laterally thereof, inverted cross-shaped frame means in a plane generally at right angles to said conductors with the upright piece secured to the upper end of said pole and the ends of the upright and transverse pieces each being located near the respective apex of said triangle, a disconnecting switch assembly mounted at each of said ends of said upright and transverse pieces, operating means on said frame means mechanically interconnecting said disconnecting switch assemblies for conjoint operation thereof between open and closed positions, and dead end means near each of said ends of said upright and transverse pieces to which said conductors can be dead ended for connection to the respective switch assembly.
 11. Disconnecting switch construction according to claim 10 wherein each switch assembly includes a stationary contact and a cooperating switch blade carried by an insulator and means pivotally mount the insulators of the switch assemblies at said ends of said upright and transverse pieces, said operating means being connected to said insulators.
 12. Disconnecting switch construction according to claim 11 wherein said operating means includes shaft means interconnecting said insulators at the ends of said transverse piece, and link means interconnecting said insulator at said end of said upright piece and said shaft means.
 13. Disconnecting switch construction according to claim 12 wherein said upright and transverse pieces are tubular and said link means and said shaft means are located respectively in said upright and transverse pieces.
 14. Disconnecting switch construction according to claim 11 wherein each of said insulators is mounted to pivot about a horizontal axis to shift said switch blade from engagement with the respective stationary contact to one side of a vertical position to the other side of said vertical position out of engagement with the respective contact whereby said switch blade in the switch closed position cannot gravitate to switch open position and in the switch open position cannot gravitate to the switch closed position.
 15. Disconnecting switch construction according to claim 11 wherein an insulator support bracket is secured to each end of said horizontal frame member and to the upper end of said vertical frame member for supporting an insulator at one end on the other end of which the respective stationary contact is mounted.
 16. Disconnecting switch construction for interconnecting conductors of a three-phase high voltage circuit each located at the apex of a triangle and for mounting on a power line pole comprising: inverted cross-shaped frame means with the upright piece adapted to be secured to the upper end of said pole and the ends of the upright and transverse pieces each being located near the respective apex of said triangle, a disconnecting switch assembly mounted at each of said ends of said upright and transverse pieces, operating means on said frame means mechanically interconnecting said disconnecting switch assemblies for conjoint operation thereof between open and closed positions, dead end means near each of said ends of said upright and transverse pieces to which said conductors can be dead ended for connection to the respective switch assembly; each switch assembly including a stationary contact and a cooperating switch blade carried by an insulator and means pivotally mounting the insulators of the switch assemblies at said ends of said upright and transverse pieces, said operating means being connected to said insulators; and an insulator support bracket secured to each end of said horizontal frame member and to the upper end of said vertical frame member for supporting an insulator at one end on the other end of which the respective stationary contact is mounted, each of said support brackets having an inner end section for mounting flatwise against the respective end of the respective frame member, an intermediate section extending at an obtuse angle from said inner end section, and an outer section extending at right angles from said intermediate section for mounting the respective contact carrying insulator in angular relation to the respective pivoted insulator. 